Many products today employ multi-layered nonwoven laminates as sub-components of their overall designs. Personal care products made from laminates such as diapers and training pants employ outercovers made from plastic films which are laminated or bonded to a fibrous nonwoven layer. The plastic film layer tends to restrict outward migration of fluids such as urine and feces while the nonwoven layer provides an exterior layer of comfort which is pleasing to the touch of the user and anyone associated with the user. One example of such a product is the Kimberly-Clark HUGGIES.RTM.PULLUPS.RTM. training pants which include a polyethylene plastic film adhesively laminated to a polypropylene spunbond nonwoven web. To make such products more attractive, the exterior nonwoven surface is often printed with a series of patterned or designs using various colored inks. Typically such inks are applied using flexographic printing processes to adhere the ink to the nonwoven layer. The fibrous polypropylene spunbond nonwoven web is in turn bonded to the plastic layer by a spray adhesive to bond the two layers together. One problem that has arisen in the past is that the printing on the exterior surface of the nonwoven is subject to sufficient amounts of abrasion to cause the ink to wear off thereby detracting from the aesthetic properties of the product.
To improve the appearance of the exterior of the diaper, at least one other diaper manufacturer, Weyerhauser Company, has produced a diaper with a two layer outercover including a nonwoven outer layer and a film inner layer. In between the two layers there is a single color design. It is believed that a single color adhesive design is applied to the interior surface of the nonwoven layer using a rotogravure single-roll printer with the nonwoven layer and the film layer subsequently being brought into contact with one another thereby forming the laminate.
Another method of printing nonwovens has included extrusion coating a layer of film onto a fibrous nonwoven layer and then printing reverse images on the film layer which are subsequently visible through both the film and nonwoven layers. Still another method of printing has been to print multiple-colored inks onto a surface of a film, coat the printed film with a spray adhesive and then laminate the printed film to a layer of nonwoven such that the inks reside between the film and nonwoven layers and are visible through the nonwoven layer.
A particular disadvantage of the foregoing processes is the number of steps and the stiff nature of the resultant product. First, one of the interior surfaces of the film/nonwoven laminate must be printed with ink and the ink must be allowed sufficient time to dry. Next, adhesive is applied across the surface (generally the entire surface) of one of the two layers and the two layers are then attached to one another. Due to the broad application of adhesive, the laminate is often stiffer than it should be. As a result, there is a need for n improved process for printing and laminating films and nonwovens.
In more simplified diaper designs, the outercover is devoid of a nonwoven layer and consists of a single layer of plastic film. Many diapers having such outercover constructions employ multi-color printing processes to impart multi-color patterns to the exterior surface of the plastic film to improve the aesthetic properties of the diaper. Such colors have been printed on the plastic film layer using either flexographic or rotogravure printing processes. In order to improve the colorfastness of the printing, the films are generally pre-treated using a corona discharge treatment. The problem with these designs is that they lack the cloth-like feel which has been found to be aesthetically pleasing.
Despite the foregoing attempts to provide films, nonwovens and laminates with multi-color printing with good abrasion resistance, there is still a need for a nonwoven laminate with improved colored adhesion utilizing a multi-color printing pattern. It is therefore an object of the present invention to provide a nonwoven laminate with a multi-colored printing pattern.
It is another object of the present invention to provide a process for making a multi-color nonwoven laminate which provides good resistance to abrasion. These and other objects of the present invention will become more apparent upon a further review of the following specification, claims and drawings.